It's plausible that it's a rebranded RockHopper, though I think HardRock would be more likely (because it was Specialized's entry level bike). Basically, any steel mountain bike of that era will be the same as any other with the same components, with some minor differences in the quality/weight of the steel.
It doesn't strike me as an amazing deal. The local craigslist is crawling with similar bikes, so hold out for one with a very good fit and in top condition (or offer less money). I got this RockHopper a couple of years ago for $120 in near perfect condition.
(I added the tires and pedals. Everything else was as pictured.)
The bike cycleheimer linked to looks like a good option.